My husband had two brief episodes of blurred vision last Jan. which an opthalmologist said was a migraine and a neurologist said was a transient ischaemic attack (mini stroke). Since it resulted in him losing his pilot's license temporarily, we did a huge amount of research. From that, I know that what you should be researching is acephalgic migraine or migraine aura without headache. I don't know if these apply to you or not, but just wanted to give you the right words - somebody did that for us and it made all the difference in our ability to research. I don't have a definitive article for you - mainly we were trying to overturn the TIA diagnosis. Good luck.